Known processes for producing optically active .alpha.-substituted organic acids from racemic .alpha.-substituted nitriles or u-substituted amides by the biochemical action of microorganisms or preparations thereof include those processes disclosed in, for example, PCT Patent Application No. 500004/1988 (WO 8607386) and JP-A-60-188355 (U.S. Pat. No. 4,812,403) (the term "JP-A" as used herein means an "unexamined published Japanese patent application"). These publications also disclose that the microorganisms used for said processes can be used for the production of optically active amino acids from aminonitriles or amino acid amides.
However, there are scarcely any known processes for producing optically active .alpha.-substituted organic acids other than amino acids from the corresponding racemic nitriles or amides by biochemical action. There are known only processes for producing optically active .alpha.-oxy acids from .alpha.-oxy acid amide compounds and specific hydroxynitriles. There are only three known microorganisms used for these processes. That is, a bacterium belonging to genus Aeromonas, a bacterium belonging to genus Moraxella and a yeast belonging to genus Torulopsis (see, JP-A-61-88894 and JP-B-54-14668 (the term "JP-B" as used herein means an "examined Japanese patent publication")).